1 MAIDEN AMERICA

IMCO made brand new gears for the SCX. Why couldn't it be done the same way they did it?

pi75

Among a combination of things like a weak design because they are designed to shift internally . The thing that makes bravos fail is actually the cases flexing and causing the gears to push apart under extreme torque causing the gears to chip. This is why all the aftermarket stuff is a lot heavier.You can not fix this problem with gears. Also a reason why the big drives have tranys.

offshorexcursion

Would't it make sense that if it was as easy as just making stronger gears Imco, Bravo Shop, Max Machine worx, etc would have done it already? Trust me I hope someone makes them some day.

1 Maiden america

I agree with that. But my guess is that Imco came out with gears that were similar to the XR gears just LARGER to gain the strength. (same with B Max upper) This is just my guess and someone can correct me if I am wrong. XR gears can only be so big and the strength, IMO, comes in size. Offroad Rock Crawlers fight with size and strength also. They want the strongest axles with the most ground clearance. Its a give and take.

I also was told when I owned my tool business, that a impact socket is actually softer then a chrome socket, to absorb the shock and not crack. The factory explained that theres way more to the design then just making the sockets "harder". To hard and they will just Shatter in pieces.

Great thread though and lots of good ideas

Panther

I've been running BMax since 2006 and have had good luck with them. The boat is a 36' Apache, flat bottom boat that weighs about 10,500 dry, without any fuel. I lost 2 mph top speed when I installed them but gained 1 mph mid-range speed with the BMax and didn't have any cavitation issues like I had with my old IMCO Extreme SC drives. I believe the main reason I lost any speed was the change from a 1.50 ratio drive to the BMax 1.30.

The first year I had them I was running 720hp. The year after that I bumped up to 830 hp and ran that for several years until last winter and now I'm pushing 875 hp. I've logged well over 350 hrs on theses drives since I've owned them. I've done full rebuilds on the lowers last winter with all new gears. They were in decent shape but I wanted to replace them anyway. I typically replace the bearings in the lowers every-other-season (minimal investment in this power range).

When I installed the drives my investment was pretty minimal, in my opinion. I paid the cost of the drives, which back then were being offered with a 2 yr warranty. I had to install new props ($1,200, much cheaper than a surface piercing prop or Herrings) and my tiebar had to be modified ($150) to fit the new wing plates. By the time I sold my IMCO Extreme SC's, which took about 2 wks., I was $5K out of pocked on the BMax's. So for me, I felt I bought 2 new drives for $5K with a 2 yr warranty and didn't have any more blown up IMCO Extreme SC's. For me it was a no-brainer at that time. If I had to do it again today (2013), I would have done it all over again but I may have chosen to use the new BMax 1.50 gear ratio that's available and I doubt I would have lost any speed. I'm still not sure I would have gone with a surface style drive these days because I have 2 small children and the thought of them swimming behind the boat with a set of Herrings gives me chills. Or, the thought of hitting a piece of driftwood and ruining a set of Herrings also give's me chills. But that's just my opinion. If I was looking for all-out performance and top speed, I would probably go the surface drive route. But then again, if I wanted all out performance I'd probably sell the Apache and get something that's faster with newer technology.

If you have any questions feel free to send me a PM.

Frank

phragle

Wasn't somebody working with Doug Fortin on gears a while ago?? I was at his shop years ago getting a porsche tranny set up for a class 1 car and remember him talking about doing something for a couple of off shore teams. That was a while ago and I do not remember specifics, but I destinctly remember it being brought up. That man knows how to make gears work.

Wolford

Of course, but it needs to fit, and function correctly in a bravo drive. So you still need a stock set of gears to work from. I have solidworks 2012, we are a manufacturer for the oil and gas industry as well as the aerospace industry. I'm currently bravo less, so let me talk to a buddy and see if he has a bravo I can dissect. Then I will have a better understanding of the whole situation.

Wolford

Never as simple as it seems, I see. What about the XR case is it "stiffer" or do the larger gears just coupe with the flex better?

Waid

pi75

Yes. because the XR gears are a straight forged gear it can witstand the small differences in backlash. If you go onto the bravoshop web site you can see the difference.

QWKRN U

Was at the Bravo Shop this weekend. He pulled apart a Bmax upper from his black thunder.850hp triples. Roughly 200hrs on the uppers. There was hardly even a wear pattern on the gears. The lowers he pulled apart that had been hard shimmed were the same way. There is definitely something he is doing that is working.

1 MAIDEN AMERICA

That's the problem with the newer XR gears. No metal on the magnet because the faces hold up great. A tooth just decides to let go nowadays. My last one busted a tooth. Rotate the gear 180* and it looked perfect. It didn't get chewed up because it locked up and broke the stub shaft in the coupler.